When shooting images, a user often takes low-quality images due to the quality of shooting devices or the user's shooting techniques, and the generally defined low quality includes image blurring caused by shake or out-of focus, image smear caused by relative movement, and excessive noise in night-view images, which usually affect the user's perception from the definition. After shooting images by using cameras, mobile phones or tablet computers, people can browse the shot images one by one, as shown in FIG. 1, a plurality of images are listed on a mobile phone album interface, and the user can open each image to judge the quality of the image, and can delete poor-quality images one by one when judging that the quality of the shot images is not good, and back up the rest images in a hard disk or in the cloud. However, the manner of viewing and identifying images one by one is very time-consuming, and in some cases, the user does not judge the quality of the images and will not delete any image and even directly back up the images without viewing and identifying the images, which leads to backup of many low-quality images and a great waste of storage space.
Therefore, how to classify images becomes an urgent problem to be resolved at present.